Locust (Salabhasana)
When this pose is demonstrated it resembles a locust (grasshopper) moving its rear ends up and down, hence the name.
Locust is one of the backward bend asanas usually performed in a sequence; first the Cobra is practiced, than the Locust followed by the Bow. Locust is a posture which turns the body out expanding the chest to face the world. It is a very stimulating, powerful and dynamic asana, one of the most demanding but also one of the most unnatural posture in Hatha yoga.
The Locust pose requires the muscles of the lower back, abdomen and legs to work with each other to achieve the lift in the lower body.
Before attempting the full Locust try to do the easier version (Half Locust), which involves lifting only one thigh at a time instead of both of them simultaneously.
As a beginner you may not have enough strength to make any movement of lifting the thighs up but you will still benefit from the effort.
As an intermediate student you will be able to lift your legs higher than the beginner student but it will require more strength in the arms, forearms and shoulders.
As an advanced student you have to be...